Conventionally, known is a method for producing a resin gear, which includes: cutting a resin sheet produced by sheet making into a gear shape; preparing a gear-shaped net-shape body by laminating a plurality of the gear-shaped resin sheets in an axial direction; and thereafter, molding the net-shape body by heat and compression (Patent Literature 1).
In accordance with this Patent Literature 1, for forming the above resin gear in a helical gear shape, teeth of the above gear-shaped resin sheets are gradually displaced and laminated, a helical gear-shaped net-shape body is prepared, and thereafter, the helical gear-shaped net-shape body is heated and compressed, so that a resin gear is molded (see paragraph 0037).
In addition, an apparatus for producing a resin gear in the above Patent Literature 1 is composed of upper and lower dies, which is so-called a cavity-core mold. For forming a resin gear in a helical gear shape, it is necessary to gradually displace and laminate teeth of the gear-shaped rein sheets in the lower die, and heat and compress them (see paragraphs 0031 and 0037).
Meanwhile, when a resin gear is prepared by laminating a plurality of resin sheets produced by sheet making in an axial direction, fibers are not entangled with each other in a direction of reinforcement fiber, and it is pointed out that resins are peeled off along this reinforcement fiber direction (Conventional Art of Patent Literature 2).